Enhancing a watermark signal extracted from an output signal of a watermarking encoder

Abstract

A device for enhancing a watermark signal extracted from an output signal of a watermarking encoder including an input signal portion corresponding to an input signal to the watermarking encoder and a watermark signal portion corresponding to the watermark signal includes an input configured to receive the input signal and the watermark signal, an enhancement module operatively connected to the input and configured to a) enhance the watermark signal at least in part by adjusting a gain of the watermark signal to obtain an enhanced watermark signal, and b) generate an enhanced output signal including an input signal portion corresponding to the input signal and an enhanced watermark signal portion corresponding to the enhanced watermark signal.

What is claimed is: 
     
       1. A device for enhancing a watermark signal extracted from an output signal of a watermarking encoder, the output signal including an input signal portion corresponding to an input signal to the watermarking encoder and a watermark signal portion corresponding to the watermark signal, the device comprising:
 an input configured to receive the input signal and the watermark signal; 
 at least one filter bank configured to divide the input signal and the watermark signal into spectral regions; 
 at least one mean/average calculator per spectral region configured to calculate at least one of root mean square (RMS) or magnitude average of the spectral region of the input signal; 
 at least one dynamic envelope calculator per spectral region configured to calculate a dynamic envelope of the at least one of the root mean square (RMS) or the magnitude average of the spectral region of the input signal to determine a masking power of each of the spectral regions of the input signal; 
 at least one envelope variability module per spectral region configured to determine a variability of the spectral region of the input signal; 
 at least one envelope detector per spectral region configured to determine energy of the watermark signal in each spectral region; 
 at least one divider per spectral region configured to calculate a ratio of the masking power of the spectral region and the energy of the watermark signal for the respective spectral region; 
 multipliers configured to adjust gains of the spectral regions of the watermark signal to produce enhanced spectral regions of the watermark signal based on the determined ratio of the masking power of the spectral region and the energy of the watermark signal for the respective spectral region and the determined variability of the respective spectral region of the input signal; and 
 a summer configured to sum the enhanced spectral regions of the watermark signal to generate an enhanced watermark signal. 
 
     
     
       2. The device of  claim 1 , wherein
 each of the multipliers receives a respective gain adjustment signal corresponding to a gain setting for the respective spectral region of the watermark signal and adjusts the gain of the respective spectral region of the watermark signal based on the received respective gain adjustment signal, the determined masking power of the respective spectral region of the input signal and the determined variability of the respective spectral region of the input signal. 
 
     
     
       3. The device of  claim 1 , wherein at least one of the summer or a second summer is configured to sum the enhanced watermark signal and the input signal to generate an enhanced output signal including an input signal portion corresponding to the input signal and an enhanced watermark signal portion corresponding to the enhanced watermark signal. 
     
     
       4. A method for enhancing a watermark signal extracted from an output signal of a watermarking encoder, the output signal including an input signal portion corresponding to an input signal to the watermarking encoder and a watermark signal portion corresponding to the watermark signal, the method comprising:
 receiving the input signal and the watermark signal extracted from the output signal of the watermarking encoder; 
 enhancing the watermark signal extracted from the output signal of the watermarking encoder at least in part by adjusting a gain of the watermark signal to obtain an enhanced watermark signal; and 
 generating an enhanced output signal including an input signal portion corresponding to the input signal and an enhanced watermark signal portion corresponding to the enhanced watermark signal. 
 
     
     
       5. The method of  claim 4 , comprising:
 dividing the watermark signal into spectral regions, 
 wherein the enhancing the watermark signal includes:
 individually enhancing the spectral regions of the watermark signal at least in part by individually adjusting gains of the spectral regions of the watermark signal and summing the individually enhanced spectral regions to obtain the enhanced watermark signal. 
 
 
     
     
       6. The method of  claim 5 , comprising:
 receiving multiple gain adjustment signals corresponding to gain settings for respective spectral regions of the watermark signal, wherein the individually enhancing of the spectral regions of the watermark signal includes enhancing the spectral regions of the watermark signal at least in part by individually adjusting the gains of the spectral regions of the watermark signal based on the received multiple gain adjustment signals. 
 
     
     
       7. The method of  claim 4 , comprising:
 dividing the input signal and the watermark signal into spectral regions; and 
 determining a masking power of the input signal for each spectral region, 
 determining energy of the watermark signal for each spectral region, 
 calculating a ratio of the masking power of the input signal for each spectral region to the energy of the watermark signal for the respective spectral region, 
 wherein the enhancing the watermark signal includes:
 individually enhancing the spectral regions of the watermark signal at least in part by individually adjusting a gain of each spectral region of the watermark signal based on the calculated ratio of the masking power of the input signal to the energy of the watermark signal for each spectral region, and 
 summing the individually enhanced spectral regions of the watermark signal to obtain the enhanced watermark signal. 
 
 
     
     
       8. The method of  claim 7 , wherein the determining the masking power of each of the spectral regions of the input signal includes:
 computing at least one of a root mean square (RMS) or a magnitude average of the spectral region, and 
 computing a dynamic envelope of the at least one of the root mean square (RMS) or the magnitude average of the spectral region. 
 
     
     
       9. The method of  claim 7 , comprising:
 receiving multiple gain adjustment signals corresponding to gain settings for respective spectral regions of the watermark signal, wherein the individually enhancing of the spectral regions of the watermark signal includes enhancing the spectral regions of the watermark signal at least in part by individually adjusting the gains of the spectral regions of the watermark signal based on the calculated ratio of the masking power of the input signal to the energy of the watermark signal for each spectral region. 
 
     
     
       10. The method of  claim 4 , comprising:
 dividing the input signal and the watermark signal into spectral regions; and 
 determining a variability of each of the spectral regions of the input signal, 
 wherein the enhancing the watermark signal includes:
 individually enhancing the spectral regions of the watermark signal at least in part by individually adjusting a gain of each spectral region of the watermark signal based on the determined variability of the respective spectral region of the input signal, and 
 summing the individually enhanced spectral regions of the watermark signal to obtain the enhanced watermark signal. 
 
 
     
     
       11. The method of  claim 10 , wherein the determining the variability of each of the spectral regions of the input signal includes:
 determining for each of the spectral regions whether energy is higher than a threshold over a period of time, and 
 assigning to each of the spectral regions a variability value relative to the other spectral regions based on how consistently energy of the spectral region is higher than the threshold over the period of time. 
 
     
     
       12. The method of  claim 10 , comprising:
 receiving multiple gain adjustment signals corresponding to gain settings for respective spectral regions of the watermark signal, wherein the individually enhancing of the spectral regions of the watermark signal includes enhancing the spectral regions of the watermark signal at least in part by individually adjusting the gains of the spectral regions of the watermark signal based on the variability of each of the spectral regions of the input signal and on the received multiple gain adjustment signals. 
 
     
     
       13. The method of  claim 4 , comprising:
 adjusting the gain of the watermark signal based on at least one of:
 a feedback measurement of the enhanced output signal, 
 station automation information including information about scheduled programming, and 
 a programming content of the input signal, wherein the programming content includes at least one of speech intensive programming and music programming. 
 
 
     
     
       14. A device for enhancing a watermark signal extracted from an output signal of a watermarking encoder, the output signal including an input signal portion corresponding to an input signal to the watermarking encoder and a watermark signal portion corresponding to the watermark signal, the device comprising:
 an input configured to receive the input signal and the watermark signal extracted from the output signal of the watermarking encoder; 
 an enhancement module operatively connected to the input and configured to:
 enhance the watermark signal extracted from the output signal of the watermarking encoder at least in part by adjusting a gain of the watermark signal to obtain an enhanced watermark signal; and 
 generate an enhanced output signal including an input signal portion corresponding to the input signal and an enhanced watermark signal portion corresponding to the enhanced watermark signal. 
 
 
     
     
       15. The device of  claim 14 , wherein the enhancement module includes:
 a filter bank configured to divide the watermark signal into spectral regions, 
 multipliers configured to adjust gains of the spectral regions of the watermark signal to produce enhanced spectral regions, and 
 a summer configured to sum the enhanced spectral regions to obtain the enhanced watermark signal. 
 
     
     
       16. The device of  claim 15 , wherein
 each of the multipliers receives a respective gain adjustment signal corresponding to a gain setting for the respective spectral region of the watermark signal and adjusts the gain of the respective spectral region of the watermark signal based on the received respective gain adjustment signal. 
 
     
     
       17. The device of  claim 14 , wherein the enhancement module includes:
 at least one filter bank configured to divide the input signal and the watermark signal into spectral regions; 
 at least one mean/average calculator per spectral region configured to calculate at least one of root mean square (RMS) or magnitude average of the spectral region of the input signal; 
 at least one dynamic envelope calculator per spectral region configured to calculate a dynamic envelope of the at least one of the root mean square (RMS) or the magnitude average of the spectral region of the input signal to determine a masking power of each of the spectral regions of the input signal; 
 multipliers configured to adjust gains of the spectral regions of the watermark signal to produce enhanced spectral regions of the watermark signal based on the determined masking power of the respective spectral region of the input signal; and 
 a summer configured to sum the enhanced spectral regions to obtain the enhanced watermark signal. 
 
     
     
       18. The device of  claim 17 , comprising:
 at least one envelope detector per spectral region configured to determine energy of the watermark signal in each spectral region; 
 at least one divider per spectral region configured to calculate a ratio of the masking power of the spectral region and the energy of the watermark signal for the respective spectral region; 
 wherein the multipliers are configured to adjust gains of the spectral regions of the watermark signal to produce the enhanced spectral regions of the watermark signal based on the determined ratio of the masking power of the spectral region to the energy of the watermark signal for the respective spectral region. 
 
     
     
       19. The device of  claim 14 , comprising:
 at least one filter bank configured to divide the input signal and the watermark signal into spectral regions; 
 at least one envelope variability module per spectral region configured to determine a variability of the spectral region of the input signal, and 
 multipliers configured to adjust gains of the spectral regions of the watermark signal to produce enhanced spectral regions of the watermark signal based on the determined variability of the respective spectral region of the input signal, and 
 a summer configured to sum the enhanced spectral regions to obtain the enhanced watermark signal. 
 
     
     
       20. The device of  claim 19 , wherein the envelope variability module determines the variability of the spectral region of the input signal by:
 determining whether energy of the spectral region is higher than a threshold over a period of time, and 
 assigning to each of the spectral regions a variability value relative to the other spectral regions based on how consistently energy of the spectral region of the input is higher than the threshold over the period of time. 
 
     
     
       21. The device of  claim 19 , wherein the enhancement module includes:
 at least one mean/average calculator per spectral region configured to calculate at least one of root mean square (RMS) or magnitude average of the spectral region of the input signal; 
 at least one dynamic envelope calculator per spectral region configured to calculate a dynamic envelope of the at least one of the root mean square (RMS) or the magnitude average of the spectral region of the input signal to determine a masking power of each of the spectral regions of the input signal; 
 at least one envelope detector per spectral region configured to determine energy of the watermark signal in each spectral region; 
 at least one divider per spectral region configured to calculate a ratio of the masking power of the spectral region and the energy of the watermark signal for the respective spectral region; 
 wherein the multipliers are configured to adjust gains of the spectral regions of the watermark signal to produce the enhanced spectral regions of the watermark signal based on the determined ratio of the masking power of the spectral region to the energy of the watermark signal for the respective spectral region and the determined variability of the respective spectral region of the input signal. 
 
     
     
       22. The device of  claim 14 , wherein the enhancement module adjusts the gain of the watermark signal based on at least one of:
 a feedback measurement of the enhanced output signal, 
 station automation information including information about scheduled programming, and 
 a programming content of the input signal, wherein the programming content includes at least one of speech intensive programming and music programming.